you could look through /var/log to check out log files. a frozen desktop could be several things. i'd start with the xfree log & system log to check for any info. just curious.............what vid card are you using & do you have nvidia drivers installed, if it's a nvidia card? those drivers are known to cause random freezes with certain cards, which is easliy fixed by adding an option to xf86config-4. also, one other thing.............are you using any power saving features? (hibernate, sleep, etc.) sometimes having those enabled can cause random freezes.